# SolidCraft tackles slow fillets and booleans with Solidcore

- Link: https://opensourcecad.nl/en/solidcraft-tackles-slow-fillets-and-booleans-with-solidcore/
- Published: 2026-10-22T21:41:34+02:00
- Author: Marijn van den Heuvel \+ AI

_This is the English reading version of the Dutch news item [SolidCraft pakt trage fillets en booleans aan met Solidcore](https://opensourcecad.nl/vibecoded-apps/solidcraft-pakt-trage-fillets-en-booleans-aan-met-solidcore/)._

SolidCraft has a familiar pain point: fillets, booleans and importing STEP files
are slow on heavy models. In a ticket on GitHub the maker explains where that comes
from and what to do about it. The solution is the new kernel Solidcore, and it is
not finished yet.

## Why it is slow

The kernel is the computing heart of a CAD program: the part that turns your sketch
into a solid, works out booleans, applies fillets and writes your model to STEP.
That is exactly where SolidCraft’s problem sits. So it is not a mistake in your 
sketch and not a setting you can switch; it is the computing core underneath.

## What is being done about it

SolidCraft is moving to a new kernel, Solidcore. It is being built on SMLib, the
kernel NVIDIA open-sourced in October 2026. The work is still going on: of the parts
a user needs, such as primitives, booleans and fillets, nothing yet works end to
end. There is no date for the switch.

The maker is clear about the current kernel: it is being replaced, so rewriting 
or speeding it up thoroughly makes little sense. Anyone wanting to put time into
SolidCraft’s performance is better off doing that in Solidcore.

**My verdict:** this is exactly why open source works out better here. You can follow
the progress of the new kernel and build along with it yourself if you like, instead
of waiting for a vendor to solve it for you. If you run into slow models, report
them: those reports become test cases for the new kernel.

The full ticket is on [GitHub](https://github.com/tangency-labs/solidcraft/issues/1597),
and the progress of the new kernel can be followed on its [progress page](https://bherbruck.github.io/solidcore/).
How Solidcore relates to the kernel that has carried open-source CAD for years is
in the [comparison with OCCT](https://opensourcecad.nl/en/solidcore-vs-occt/).